Aerial fire suppression system

ABSTRACT

A fire suppression apparatus for fighting fires from a vehicle configured for flight is disclosed, comprising a foam and water held in separate containers aboard the vehicle that when mixed forms a fire retardant, a pump driven by an electric motor to pressurize the fire retardant, the pump including an air induction valve where air is drawn into a suction end of the pump and pressurized together with the fire retardant, and an aimable boom connected to the pump by a conduit, the boom including a nozzle on a distal end of the boom from which the pressurized fire retardant and air is dispensed toward a target.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Non-Provisional patentapplication Ser. No. 13/750,623, filed on Jan. 25, 2013 and published asU.S. Publication No. 2013/0199806, which claims the benefit of U.S.Provisional Patent Application No. 61/591,791, filed Jan. 27, 2012.These applications are incorporated herein by reference in theirentirety.

BACKGROUND

This application relates generally to systems for dispensing liquidsfrom an aerial vehicle, and particularly to fire suppression systemsusable in connection with aerial vehicles, such as aircraft androtorcraft.

The design and implementation of firefighting systems for use inairborne vehicles is a difficult endeavor at least because airbornevehicles, such as aircraft and rotorcraft (i.e., helicopters), havelimited volume and payload capability, and because such systems aresubject to rigorous government certification requirements to protect thesafety of those flying on such vehicles as well as to protect people andproperty on the ground. Thus, airborne firefighting systems should berelatively small and lightweight, simple and safe to operate, withminimum impediments to government certification, while providing thelongest possible endurance and the best possible effectiveness at a firelocation.

Compressed Air Foam Systems (CAFS) are known in the firefightingindustry for fighting fires from vehicles and platforms on the ground.Such systems include the use of a foaming agent that when combined ormixed with water, enhances the fire suppression capability of wateralone. For example, when dispensed onto a fire, a water/foam mixturecompared to water alone has the advantage of adhering to horizontal andvertical surfaces of a structure for long duration fire retardancy,acting as a surfactant thereby preventing re-ignition of the fire, inthe case of a multi-story building, limiting water damage to the floorsbelow the fire, and magnifying the fire suppression qualities of waterby up to seven times.

Known CAFS systems for ground-based vehicles and firefighting platformsmay include compressed air or inert gas injected into the water/foammixture to aerate the water/foam mixture and to eject the water/foammixture from a nozzle at relatively high velocities toward a relativelydistant target. Compressed air or inert gas for this purpose is usuallyprovided in the form of pressurized tanks or bottles or by one or moremechanical air compressors.

However, use of pressurized tanks or bottles or air compressors as asource for pressurized air can consume valuable space and energyresources on an airborne vehicle, are relatively heavy thereby reducingthe payload available for consumable fluids such as water, foam, andfuel, and increase the risk of accidents due to the hazards associatedwith pressurized systems. In addition, pressurized tanks must beattached securely to an airframe, which may lengthen turnaround timeswhen replacing depleted air tanks. Moreover, structural and weightlimitations prevent pressurization of one or more water tanks carriedaboard aircraft or rotorcraft where pressurized water tanks wouldotherwise be usable for propelling water or a water/foam mixture towarda distant target.

What is needed is a firefighting system configured for use in airbornevehicles, which overcomes the aforementioned limitations of existingCAFS systems.

SUMMARY

A fire suppression apparatus for fighting fires from a vehicleconfigured for flight is disclosed, comprising a fire retardantcomprising a foam mixed with water, a foam proportioner for mixing thefoam with the water at a selectable foam to water ratio, a gas generatorfor generating a gas for expelling the fire retardant from the vehicletoward a fire, the gas formed from the combustion of a fuel and anoxidizer in a combustion chamber associated with the gas generator, thecombustion chamber comprising no moving parts, and an aimable boomcomprising a nozzle on a distal end of the boom from which the fireretardant is dispensable toward the fire.

The foam proportioner of the fire suppression apparatus may beconfigured to receive the gas generated from the gas generator forinjection into the fire retardant for expelling the fire retardant fromthe boom. The foam to water ratio of the fire suppression apparatus mayrange from approximately 0.1% to approximately 10.0%. The foam to waterratio of the fire suppression apparatus may range from approximately0.4% to approximately 1.0%. The fuel and oxidizer of the firesuppression apparatus may be stored in respective fuel and oxidizertanks on the vehicle. The oxidizer may be oxygen formed from thedecomposition of hydrogen peroxide, the decomposition of hydrogenperoxide permitted while the apparatus is in flight. The fuel isselected from the group consisting of kerosene, Jet A, methanol,tetraglyme, ethanol, and methanol, furfuryl alcohol, triglyme, ordimethyl sulfoxide (DMSO).

In another embodiment, a fire suppression apparatus for fighting firesfrom a helicopter is disclosed, comprising a foam and water held inseparate containers aboard the helicopter that when mixed forms a fireretardant, a pump driven by an electric motor, the pump including an airinduction valve where air is drawn into a suction end of the pump andpressurized by the pump together with the fire retardant, and an aimableboom connected to the pump by a conduit, the boom including a nozzle ona distal end of the boom from which the pressurized fire retardant andair is dispensed toward a target.

The fire retardant may include a foam to water ratio ranging fromapproximately 0.1% to approximately 10.0%. Approximately 30 CFM toapproximately 50 CFM of air may be pressurized with the fire retardantto approximately 125 psi by the pump. The fire retardant including theair may be expelled from the nozzle at a variable rate up toapproximately 150 gpm.

The boom may be supported by a rotatable turret, which may include afirst actuator for rotating the turret and a second actuator forvertically manipulating an aimpoint of the boom. The turret and the boomare programmable to automatically return to a home position upon theoccurrence of an event. The event may be associated with a function ofthe helicopter such as a power failure. The distal end of the boom mayextend beyond the tip of a rotor associated with the helicopter. Theboom may dispense the pressurized fire retardant including the air atthe target positioned downrange of a starboard side or a port side ofthe helicopter. An electronic control system may be connected to theboom to manipulate an aimpoint of the boom toward the target.

In another embodiment, a fire suppression apparatus for fighting firesfrom a helicopter, comprising a tank assembly attachable to thehelicopter, the tank assembly supporting a foam tank for housing a foam,a water tank for housing water, and a foam pump for pumping the foamfrom the foam tank to the water tank to form a fire retardant, apowerpack supported on one end of the tank assembly, including a pumpdriven by an electric motor, the pump including an air induction valvewherein air is drawn into a suction end of the pump and pressurized bythe pump together with the fire retardant, and a cannon assemblysupported on an opposite side of the tank assembly, comprising a boomhaving a nozzle positioned at a distal end of the boom, the proximal endconnected to a conduit connected to the pump for conducting the aeratedfire retardant therethrough, and a rotatable turret supporting the boom,a first actuator for rotating the turret and a second actuator formoving the distal end of the boom.

The fire retardant may include a foam to water ratio ranging fromapproximately 0.1% to approximately 10.0%. Approximately 30 CFM toapproximately 50 CFM of air may be pressurized with the fire retardantto approximately 125 psi by the pump. The fire retardant including theair may be expelled from the nozzle at a variable rate up toapproximately 150 gpm.

The distal end of the boom may extend beyond the tip of a rotorassociated with the helicopter. The boom may dispense the pressurizedfire retardant including the air at a target positioned downrange of astarboard side or a port side of the helicopter. The cannon assembly maybe controllable by a joystick to manipulate an aimpoint of the boomtoward a target. The fire suppression apparatus may include an infraredvision apparatus. The fire suppression apparatus may also include adistance measuring system for identifying a relative position and/ordistance of the nozzle relative to a target.

In another embodiment, a fire suppression apparatus for fighting firesfrom a helicopter is disclosed, comprising a tank assembly attachable tothe helicopter having a foam and water held in separate containers thatwhen mixed forms a fire retardant, a retractable pump system attached tothe tank assembly or the helicopter for refilling the containerassociated with the water when the helicopter is in flight, a powerpacksupported on one end of the tank assembly, and an aimable boom supportedon an opposite end of the tank assembly and connected to the pump by aconduit, the boom including a nozzle on a distal end of the boom fromwhich the pressurized fire retardant and air is dispensed toward atarget. The retractable pump system includes a collapsible hoseconnected on a first end to a reversible, motorized reel for deployingand retrieving the hose, and a water pump positioned on a second end ofthe hose for pumping water from a water source to the containerassociated with the water. The powerpack includes a pump driven by anelectric motor, the pump including an air induction valve wherein air isdrawn into a suction end of the pump and pressurized by the pumptogether with the fire retardant.

The boom may be programmable to automatically return to a positionalongside a fuselage of the helicopter with the distal end pointing inthe direction of a nose of the helicopter upon the occurrence of anevent. A joystick may be included for manipulating an aimpoint of theboom. The joystick may variably adjust a flow rate of the pressurizedcombination of fire retardant and air dispensed from the boom.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustrating one embodiment of an aerial firesuppression system.

FIG. 2 is a detailed schematic of the gas generator of the embodiment ofFIG. 1.

FIG. 3 is a schematic illustrating an alternative embodiment of anaerial fire suppression system.

FIG. 4 illustrates an exemplary infrared camera mounted on a boom of anexemplary aerial fire suppression system.

FIG. 5 illustrates a detailed perspective view of a portion of anexemplary aerial fire suppression system.

FIG. 6 illustrates an exemplary tank assembly of an exemplary aerialfire suppression system.

FIG. 7 illustrates a detailed perspective view of a portion of anexemplary aerial fire suppression system.

FIG. 8 illustrates a detailed perspective view of a portion of anexemplary aerial fire suppression system.

FIG. 9 illustrates an exemplary aerial fire suppression system in use.

FIG. 10 illustrates a right front perspective view of another embodimentof an aerial fire suppression system.

FIG. 11 illustrates a left front perspective view of the embodiment ofFIG. 10.

FIG. 12 illustrates a left rear perspective view of the embodiment ofFIG. 10.

FIG. 13 illustrates a right rear perspective view of the embodiment ofFIG. 10.

FIG. 14 illustrates a partial detailed right rear perspective view ofthe embodiment of FIG. 10.

FIG. 15 illustrates a perspective view of an exemplary retractable pumpsystem usable in connection with an embodiment of an aerial firesuppression system.

FIG. 16 illustrates a partial front perspective view of the retractablepump system shown in FIG. 15.

FIG. 17 illustrates a partial rear perspective view of the retractablepump system shown in FIG. 15.

FIG. 18 illustrates a partially exploded perspective view of the cannonassembly shown in FIG. 10.

FIG. 19 illustrates a perspective view of the operator station shown inFIG. 10.

FIG. 20 illustrates a schematic of one embodiment of the aerial firesuppression system of FIG. 10.

FIG. 21 illustrates a partial detailed right front perspective view ofthe powerpack shown in FIG. 20.

FIG. 22 illustrates a partial detailed right front perspective view ofthe powerpack shown in FIG. 20.

FIG. 23 illustrates a partial detailed left front perspective view ofthe powerpack shown in FIG. 20.

FIG. 24 illustrates a partial detailed top perspective view of thepowerpack shown in FIG. 20.

FIG. 25 illustrates a schematic of another embodiment of the aerial firesuppression system of FIG. 10.

FIG. 26 illustrates a partial detailed right front perspective view ofthe powerpack shown in FIG. 25.

FIG. 27 illustrates a partial detailed top perspective view of thepowerpack shown in FIG. 25.

FIG. 28 illustrates a top view of a helicopter having the aerial firesuppression system of FIG. 10 mounted thereto.

FIG. 29 illustrates a left side view of the helicopter shown in FIG. 25having the aerial fire suppression system of FIG. 10 mounted thereto.

FIG. 30 illustrates a front view of the helicopter shown in FIG. 25having the aerial fire suppression system of FIG. 10 mounted thereto.

DETAILED DESCRIPTION

Although the figures and the instant disclosure describe one or moreembodiments of a fire suppression system for aerial vehicles, one ofordinary skill in the art would appreciate that the teachings of theinstant disclosure would not be limited to such systems, and insteadwould also have utility on ground-based platforms and on airborneplatforms for use in other industries, or wherever a volume of water,water mixture, or fluid of any kind is needed to be delivered to atarget at a distance from the initiating platform. In one embodiment, asystem of the instant disclosure may be used to fight fires in buildingsand structures of all shapes and sizes, including on high-rise buildingsand oil rigs. In another embodiment, a system of the instant disclosuremay be used to fight wildfires. In another embodiment, a system of theinstant disclosure may be used to clean buildings of all shapes andsizes, including mosques, water towers, and high-rise buildings. Inanother embodiment, a system of the instant disclosure may be used toclean high tension wire insulators on electrical towers and onwindmills. In another embodiment, a system of the instant disclosure canbe used to deice structures, such as aircraft, windmills, power lines,and the like. In another embodiment, a system of the instant disclosurecan be used to decontaminate an area, provide crowd control, or provideoil spill remediation.

Turning now to the figures, wherein like reference numerals refer tolike elements, FIG. 1 shows an exemplary aerial fire suppression system10 configured for use in an aerial vehicle, such as an aircraft or ahelicopter, for use in suppressing wildfires or high-rise fires, amongothers. System 10 comprises water tank 20 and foam tank 30 for storingwater 24 and foam (or foam concentrate) 34, respectively, for use increating a water/foam mixture for use in fighting fires. In aconfiguration of system 10, foam tank 30 comprises approximately 5% toapproximately 10% by volume of the amount of water carried in water tank20. A suitable foam is Phos-Chek® WD881 Class A Foam, which is availablefrom ICL Performance Products LP of St. Louis, Mo.

Water 24 from water tank 20 and foam or foam concentrate 34 from foamtank 30 is brought together in foam proportioner 90 and mixed therein.System 10 includes water pump 22 and foam pump 32 connected to watertank 20 and foam tank 30, respectively, for drawing water 24 and foam orfoam concentrate 34 from water tank 20 and foam tank 30, respectively,and for delivery of the water 24 and foam or foam concentrate 34 to foamproportioner 90 at a relatively large volumetric rate. Water pump 22 maybe sized and configured to draw water 24 from water tank 20 and deliverit to foam proportioner 90 at a rate of approximately 20 toapproximately 150 gallons per minute (gpm).

Foam proportioner 90 may be configured to selectively and automaticallyprovide a desired ratio of foam to water ranging from approximately 0.1%to approximately 10.0%, and preferably from 0.4% to approximately 1.0%.Foam proportioner controller 92 connected to foam proportioner 90provides an operator with the ability to select or otherwise input adesired foam to water ratio provided by foam proportioner 90 duringoperation of system 10. In one embodiment, foam proportioner 90 isconfigured to provide one of a number of pre-set foam to water ratiosaccording to the water/foam coverage needs on a fire. A suitable foamproportioner 90 for system 10 is a 2000 series unit available fromPentair Water-Foam Pro of New Brighton, Minn. 55112.

System 10 of FIG. 1 also shows fuel tank 40 and oxidizer tank 60 forstoring a fuel and an oxidizer, respectively, onboard the aerialvehicle. Fuel 44 from fuel tank 40 and oxidizer 64 from oxidizer tank 60may be brought together and ignited in gas generator 70 to form asubstantial volume of exhaust gases 80 for injection into the water/foammixture via foam proportioner 90. In one embodiment, exhaust gases 80may be supplied to foam proportioner 90 at a rate of approximately 70cubic feet per minute (CFM).

As best shown in FIG. 2, gas generator 70 may include injector 72 forreceiving and injecting fuel 44 and oxidizer 64 into combustion chamber74. To inject fuel 44 and oxidizer 64 into combustion chamber 74,injector 72 may comprise injector elements, such as injector posts, foreach of fuel 44 and oxidizer 64. Injector 72 may further comprise one ormore features to help achieve stable combustion of fuel 44 and oxidizer64, such as a baffle apparatus. In one embodiment, a baffle apparatusmay be formed by arranging fuel and/or oxidizer injector elements, suchas injector posts, to form one or more baffles inside a fuel/oxidizermixing zone of combustion chamber 74 to help achieve stable combustionof fuel 44 and oxidizer 64.

Depending on the characteristics of fuel 44 and oxidizer 64, fuel 44 andoxidizer 64 may spontaneously or hypergolically ignite upon contact withone another in combustion chamber 74 or may be caused to ignite using anexternal energy source, such as a glow plug, a spark plug, or apyrotechnic device. In one embodiment, fuel 44 and oxidizer 64 exist inliquid form, but either may be used in any combination of solids,liquids or gases or hybrids of these without departing from the scope orprinciples of the instant disclosure.

Gas generator controller 76 is connected to gas generator 70 formonitoring and automatically adjusting the mixture ratio of fuel 44 tooxidizer 64 by opening and closing one or more fuel and/or oxidizervalves. Gas generator controller 76 may be configured to monitor andcontrol characteristics of the combustion process, such as temperatures,pressures and composition of combustion products, and the gas flow rateand delivery of exhaust gases 80 to foam proportioner 90. Gas generatorcontroller 76 may be configured to automatically and safely terminatethe combustion process upon the occurrence of an event, such as thereceipt of a signal corresponding to low fuel or oxidizer levels or of asignal or a command, such as one initiated by an operator or as a resultof a sensor reading, by automatically closing the one or more fueland/or oxidizer valves in a predetermined sequence, timing, and rate tocease delivery of fuel 44 and/or oxidizer 64 to gas generator 70. Gasgenerator controller 76 may be configured for open loop or closed loopcontrol of these elements and functions. In one embodiment, gasgenerator controller 76 is configured to automatically terminate thecombustion process upon loss of vehicle electrical power, as may occuras a result of an inflight shutdown of one or more flight-sustainingengines of the aerial vehicle or the shutdown of one or more onboardengines or auxiliary power units (APU's). System 10 can be configured toautomatically reconfigure itself into a “safe” mode to cease dispensingthe water/foam mixture, to cease combustion in gas generator 70, and tostow boom 100 (discussed below) to minimize workload of the occupants ofthe vehicle in the event of, for example, an emergency involving theaerial vehicle.

Turning again to FIG. 1, system 10 may include fuel pump 42 and oxidizerpump 62 connected to fuel tank 40 and oxidizer tank 60, respectively,for drawing fuel 44 and oxidizer 64 from fuel tank 40 and oxidizer tank60, respectively, and delivery of fuel 44 and oxidizer 64 to gasgenerator 70 at a relatively large volumetric rate. Fuel 44 and/oroxidizer 64 may alternatively be gravity fed or pressure fed to gasgenerator 70 if, for example, fuel tank 40 and/or oxidizer tank 60 areeither pressurized or are configured for gravity delivery of the fluidsfrom therein.

In situations where a foam proportioner is not needed or desired, foamor foam concentrate 34 may alternatively be premixed with water 24 at apredetermined ratio to form a batch, which may be carried onboard theaerial vehicle in a water/foam tank. In this situation, exhaust gases 80may be brought together and mixed with a flow of the water/foam mixtureto propel the water/foam/gas mixture from boom 100 toward a target.

Upon exiting foam proportioner 90, the mixed water/foam/exhaust gasmixture 98 is then delivered to boom 100 and dispensed from boom 100 vianozzle 130 toward the aim point of boom 100. Exhaust gases 80 aid in theformation of bubbles in boom 100 and increase the distance at which thewater/foam mixture is discharged from nozzle 130. Boom 100 mayincorporate lightweight materials and geometry uniquely suited to permita relatively lengthy boom 100 while providing a flow rate of fluidstherefrom sufficient to suppress a fire located a substantial distanceaway from the vehicle. For example, boom 100 may be configured from oneor more pieces and may be constructed of a composite material to providesufficient rigidity to withstand excessive bending or deflection alongits length, especially in the presence of, for example, rotor downwashwhen installed on a helicopter.

Boom 100 may also be configured to extend beyond the rotor tip diameterof a helicopter, for example, to avoid undesirable, pre-dispersion oratomization of the water/foam mixture. In one embodiment, boom 100 isapproximately 6.7 to 7.3 meters long and extends at least approximately1 meter past the rotor tip. At least the distal end of boom 100 may beconstructed of one or more materials that provide electrical insulatingproperties to prevent the conduction and transmission of electricityshould boom 100 be used in or near electrical power lines, for example,such as when fighting fires situated in close proximity to electricalpower lines or when cleaning power line insulators on electrical powerline towers. Besides composite materials, boom 100 may be constructedfrom other materials that provide the foregoing and other desirableproperties and functionality, including wound carbon fiber andfiberglass, matt resin, and aluminum, among others. In view of itslength beyond the rotor tip, boom 100 may be formed into a relativelylight yet strong and deflection resistant structure to avoid excessiveshifting of the center of gravity of the aerial vehicle and to avoiddeflection of the distal tip of boom 100 into the path of the rotorblades.

Boom 100 may be constructed to permit its telescoping extension andretraction to, for example, provide compact stowage during groundoperations and during flight while also providing the ability toposition the distal end of nozzle 130 beyond the rotor tip while in useand on station at the location of a fire. Boom 100 may alternatively beconstructed as a fixed length.

Boom 100 may be configured to operate in a “wet” configuration or in a“dry” configuration. For operation in a “wet” configuration, the workingfluid, such as a water/foam mixture, is communicated through boom 100 tonozzle 130 and “wets” the internal surfaces of boom 100. By contrast,boom 100 may be configured in a “dry” configuration in which an internalhose communicates the working fluid therein to nozzle 130. A “dry”configuration involving an internal hose may not easily allow boom 100to also be of a telescoping configuration, whereas boom 100 having a“wet” configuration coupled with a telescoping configuration may lead tobinding of or leakage through telescoping elements of boom 100.

System 10 may be configured to include two or more of booms 100 fordispensing fluids at multiple aim points or for increasing the volumeand/or rate of dispensed fluids from a single aerial vehicle. The one ormore booms 100 may be deployed toward the side of the aerial vehicle ortoward the front of the aerial vehicle. Sideward deployment of boom 100may reduce pilot workload if a dedicated operator of system 10 islocated on the aerial vehicle or is remotely operating system 10 therebyallowing the pilot to fly the vehicle while also improving thefirefighters' ability to target the fire independent of vehiclemovement. Sideward deployment helps the pilot position and orient thevehicle to obtain optimum flight characteristics, and facilitates use ofemergency escape routes because the vehicle is pointing away from thefire, potentially in the direction of intended travel. By contrast,forward deployment of boom 100 in a rotorcraft can negatively impactrotorcraft stability because a tail wind may be created by theconsumption of air by the fire.

System 10 may be configured to deliver the water/foam mixture fromnozzle 130 at relatively low pressure but at relatively high volumes tosuppress a fire downrange. The pressure for low pressure configurationsof system 10 may range from approximately 50 to approximately 200 poundsper square inch (psi), depending on how far downrange the water/foammixture or other fluid is desired to be delivered. In one embodiment,system 10 is configured to deliver the water/foam mixture from nozzle130 at approximately 125 psi at a flow rate of approximately 150 gpm toa distance of approximately 132 feet from nozzle 130, which correspondsto approximately 150 feet from the proximal end of boom 100 if boom 100is approximately 7 meters long. In this way, system 10 may be used tosuppress fires at a significant distance from the firefighting platform,including buildings located in urban areas, such as high rise buildingsand warehouses. In another one embodiment, system 10 is configured todeliver the water/foam mixture from nozzle 130 at approximately 125 psiat a flow rate of approximately 20 gpm to a distance of approximately 65feet from nozzle 130.

System 10 may alternatively be configured to provide relatively lowvolumes of fluid at relatively high pressure to, for example, be usedfor pinpoint cleaning of insulators on electrical high tension wiretowers, for cleaning windmills and the like, or for deicing structures,vehicles and the like. In one embodiment, system 10 may be configuredfor cleaning of high tension wire insulators to deliver a fluid fromnozzle 130 at approximately 1500 psi to provide approximately 5.5 toapproximately 6.0 gpm to a distance of approximately 12 to approximately14 feet from nozzle 130, which exceeds the distance currently providedby known cleaning systems of approximately 3 to approximately 6 feetfrom a nozzle.

In one embodiment, system 10 includes a winch driven, manually operated,boom system with handlebars for manually guiding boom 100 left, right,up, and down. Springs 111 and/or hydraulic or pneumatic cylinders mayassist an operator of boom 100 to move boom 100 vertically. In anotherembodiment, instead of the manually operated, winch driven boom system,system 10 may include turret 110 to permit powered or power assistedmanipulation of boom 100 both vertically and horizontally.

An operator, whether it is the pilot, an onboard operator, or a remotelylocated operator, may manipulate the aim point of boom 100 using, forexample, a joy stick. In another embodiment, the operator may manipulatethe aim point of boom 100 using a set of handlebars, a steering wheel orany other known steering apparatus to steer boom 100 toward an aimpoint. As shown in FIG. 1, boom 100 may be connected to turret 110,which may or may not include a drive system for altogether moving or atleast assisting the movement of boom 100 as directed by an operator. Ifturret 110 includes a drive system, turret 110 may additionally beconfigured to stow boom 100 in a “home position” when not in use toenhance the safe operation of the aerial vehicle during flightoperations and to permit, for example, easy and safe ingress and egressto and from the location of the fire.

Linear and rotary actuators may be programmed to control the directionand speed of movement of boom 100 and turret 110, respectively, via thejoy stick or other steering apparatus. Compound (diagonal) movement ofboom 100 may be achieved by engaging the linear and rotary actuatorssimultaneously, perhaps at different rates. In one embodiment,rotational movement of boom 100 may range from pointing approximatelytoward the nose of the aerial vehicle (i.e., forward) for stowage duringtransit of the aerial vehicle, to approximately 110 degrees aft duringfire suppression operations. In an embodiment for rotorcraftimplementations, vertical movement of boom 100 may range fromapproximately level (to avoid interference with the rotor) toapproximately 40 degrees downward. For aircraft implementations,vertical motion of boom 100 may range from approximately horizontally toapproximately 40 degrees downward. A mechanical or an electromechanicallock may be implemented to stow boom 100 for stowage for transit of thevehicle. One or more position sensors may be employed to provide one ormore signals corresponding to the position of boom 100. The one or moresignals may be used to disengage or engage one or more of the linear androtary actuators, and thereby movement, of boom 100.

In one or more embodiments, system 10 may include infrared visionapparatus 115, distance measuring apparatus 120 comprising a laser fordetermining the distance between the aerial vehicle and any obstructionsor buildings, and an anti-cavitation device in water tank 20 forminimizing the chances of drawing air rather than water 24 from watertank 20 by water pump 22. Infrared vision apparatus 115 may compriseinfrared camera 117, such as the EVS3 9 Hz infrared camera availablefrom FLIR Systems, Inc. of Goleta, Calif. 93117, to help identify firehot spots through fog, dust, and smoke and in total darkness. In oneembodiment, as shown in FIG. 4, infrared camera 117 may be mounted onboom 100. In another embodiment, infrared camera 117 may be mountedelsewhere on a component of system 10 or on a component of the aerialvehicle. In one embodiment, imagery from one or a multiple of infraredcameras 117 may be fed to display 160 mounted on or near turret 110 tobe viewed by an operator of turret 110. Alternatively, imagery from oneor a multiple of infrared cameras 117 of system 10 may be fed tomultiple displays in real-time. Such displays may include a display inthe cockpit for the pilot, a display on a helmet mounted vision systemworn by the pilot or by one or more crew members or operators of system10 onboard the aerial vehicle, a display located remotely from theaerial vehicle either on the ground or in another aerial vehicle, and adisplay associated with any number of handheld devices, includingcellular phones or computer tablet devices.

Turning to FIG. 3 there is shown an alternative embodiment for system10. In particular, system 10 of FIG. 3 includes reactant tank 50 forstoring reactant 54 therein. In one embodiment, reactant 54 compriseshydrogen peroxide, which when allowed to decompose in the presence of acatalyst, such as silver, forms steam and gaseous oxygen. The oxygen maythen be combined with fuel 44 in gas generator 70 whereupon fuel 44 isignited in combustion chamber 74 to form exhaust gases 80. Exhaust gases80 comprising a relatively high volume of gas on the order ofapproximately 70 CFM may be fed into foam proportioner 90 whereupon thewater/foam/gas mixture 98 may thereafter be delivered to boom 100 andultimately dispensed from nozzle 130 upon a distant target.

As a reactant, hydrogen peroxide may range in purity from approximately90% to approximately 50%. In one embodiment, the decomposition ofreactant 54 occurs in a reaction tank downstream of reactant tank 50 butupstream of gas generator 70. Pressure relief valves may be placed ontanks and on fluid or gas lines wherever pressure needs to be releasedautomatically for purposes of maintaining a proper margin of safety ofsystem 10.

Fuel 44 may be one of kerosene, Jet A, methanol, tetraglyme, ethanol,methanol, furfuryl alcohol, triglyme, or dimethyl sulfoxide (DMSO).Depending on the characteristics of the reactant, a suitable catalyst tohelp speed the decomposition reaction and therefore production of theoxidizer may be from the group consisting of manganese acetatetetrahydrate, sodium borohydride, ferrous chloride, silver (colloidal),silver salts, potassium permanganate, and sodium permanganate. In oneembodiment, system 10 includes a relatively safe, non-toxic or very lowtoxicity fuel, reactant and/or oxidizer, and exhaust gases to promoterelatively safe handling and/or operation and require minimal personnelprotection.

Turning to FIG. 5, there is shown a detailed view of a portion of anexemplary system 10. For example, there is shown turret 110, which asdescribed above, may include a manually operated or a power assisted orpowered configuration. Also shown is boom 100, with infrared camera 117of infrared vision apparatus 115, which can provide an image to adisplay, such as display 160, as described above. Also shown is chair150 to permit an operator onboard the vehicle to direct the aim point ofboom 100. Further shown is powerpack 140, which can be configured tocounterbalance turret 110 and boom 100 when extending out the side ofthe aircraft or rotorcraft, can provide lateral stability and control ofthe aerial vehicle when in service. Powerpack 140 may include, forexample, gas generator 70, foam proportioner 90, one or more of thepumps described above, or any other article carried by the aerialvehicle that may assist powerpack 140 in providing the counterbalancingfunction. FIG. 5 shows an exemplary rail system 170 for mounting turret110, chair 150, and powerpack 140 onto an aerial vehicle.

Electrical power to operate system 10, including turret 110 and boom100, may be derived from a nonessential electrical bus of the aerialvehicle, from an electrical generator connected to the engine ortransmission of the aerial vehicle, or from an auxiliary power unit(APU). All of the fluid pumps described above may be electrically drivenusing electrical power from the sources noted above, or may bemechanically driven through mechanical links to onboard engines, or maybe turbine driven using a portion of exhaust gases 80 to drive one ormore turbine wheels connected to one or more impellers or inducers ofthe pumps, or a combination of any of these methods.

One or more of the pumps described above, namely fuel pump 42, oxidizerpump 62, water pump 22 and foam pump 32 and reactant pump 52 may bepowered either mechanically or electrically from the aircraft orrotorcraft systems. For example, fuel pump 42 may be configured as anelectric pump that draws electrical current from a nonessential mainelectrical bus of the aircraft or rotorcraft, or from a generatorconnected either to the rotor or engine system, or from a separateauxiliary power unit (APU). Foam proportioner 90, turret 110, foamproportioner controller 92, and gas generator controller 76 may all bepowered in the same way.

A battery may be configured as a backup electrical power supply to boom100 and to turret 110 to enable system 10 to automatically stow, or thepilot, onboard operator, or remote operator to manually stow, boom 100in a safe, forward-projecting configuration for egress of the airvehicle on-station and for landing of the air vehicle should the airvehicle or system 10 otherwise lose electrical power. As shown in FIG.7, an alternative embodiment of turret 110 includes return springs 111for assisting a boom operator with vertical movement of boom 100 and toreturn boom 100 to the horizontal position when not manually commandedby the boom operator. As shown in FIG. 8, an embodiment of turret 110includes gas struts 112, which may provide a fail-safe return of boom100 to the horizontal position should the vehicle lose power when boom100 is under manual, power assisted, or powered control by the boomoperator.

Turning to FIG. 6, tanks 20, 30, 40, 50 and 60 may be mounted externallyto the aerial vehicle as part of tank assembly 180. Tanks 40, 50 and/or60 may alternatively be mounted in powerpack 140, leaving only tanks 20and 30 mountable in tank assembly 180 or in a separate structure. All ofthese tanks may be internally mounted to the aerial vehicle but doing somay limit multi-mission capability and flexibility by consuming valuableinternal volume of the vehicle. Foam tank 30 may comprise a bladder forenabling an aerial vehicle to drop fire retardant vertically whenneeded, such as on wildfires or on warehouse building fires or wheneverhorizontal delivery of retardant is not needed. The bladder may behoused internally to water tank 20.

Although not shown on the figures, system 10 may include piping forcommunication of fluids and gases to and from various elements of system10, valves, including pressure relief valves, temperature, pressure, andposition sensors, flow meters, and controllers. System 10 may includeother, similar elements without departing from the scope or principlesof the instant disclosure.

In addition, the aerial vehicle may include retractable ornonretractable refill systems configured for use on rotorcraft or fixedwing aircraft. In an embodiment including a rotorcraft, refill cycletimes while hovering over a water source, such as a reservoir or a lake,may range from approximately 25 seconds to approximately 60 seconds toreload water tank 20 with water. In an embodiment, foam refilling may berequired after approximately 5 to approximately 10 water cyclesdepending upon the ratio of foam to water used.

In an embodiment, fuel tank 40 and oxidizer tank 60 may each compriseapproximately 2.0 gallons to approximately 3.0 gallons of fluid whilefoam tank 30 may comprise approximately 36 gallons of foam 34 and watertank 20 may comprise approximately 600 gallons of water 24 that isrefillable using an inflight refilling system, the combination providingapproximately one hour of water/foam fire retardant dispensed withexhaust gases 80 during normal use of system 10, which approximatelycoincides with approximately 60 minutes of available fuel (plus 30minutes of reserve fuel) that a rotorcraft may carry on a single missionto power the vehicle for flight.

In one embodiment, fuel tank 40, oxidizer tank 60 (or reactant tank 50)may be swapped and replaced, and foam tank 30 may be refilled, on theorder of a few minutes by ground personnel by employingquick-disconnects for all pipe interconnects to other elements of system10. System 10 can therefore dramatically improve on-station enduranceand utility, and minimize periods of downtime, by the firefightingplatform.

Turning to FIG. 9 there is shown an exemplary system 10 attached tohelicopter 190 for fighting a fire in a high rise building. In thisdepiction, boom 100 is shown being oriented approximately 90 degreesclockwise from the nose of helicopter 190. With the vehicle alreadypointing in a potential direction of travel, quick and automatic stowageof boom 100 in the forward position permits easy egress of helicopter190 from the firefighting station should an emergency involving theaerial vehicle occur. FIG. 9 also shows hover pump system 185 toreplenish water tank 20 with water from a water source, such as areservoir, pond, lake, and the like while helicopter 190 hovers overheadthe water source. As shown, hover pump system 185 includes water pump187 located at the distal end of hose or conduit 186 for submersion intothe water source, and rotatable elbow 188 to permit helicopter 190 landwhile hover pump system 185 is installed thereto.

Referring now to FIGS. 10-14, there is shown system 200 configured foruse in an aerial vehicle, such as an aircraft or a helicopter, for usein suppressing wildfires or high-rise fires, among others. System 200includes many of the same or similar features and functionality asdescribed above for system 10, but incorporates different approaches, asdescribed more fully below, to generate and utilize gas aboard an aerialvehicle for injection into the water/foam mixture for delivery by boom100 toward a target.

System 200 includes tank assembly 180, powerpack 140, cannon assembly210, operator station 240, as well as various plumbing, wiring,fittings, and supports to interconnect the foregoing. Cannon assembly210 and powerpack 140 are both supported by tank assembly 180, which isconfigured for mounting externally to the fuselage of an aerial vehicle.Cannon assembly 210 is mounted on one side of tank assembly 180 whilepowerpack 140 is mounted to an opposite side of tank assembly 180. Inthis way, the weight of cannon assembly 210 may be counterbalanced bythe weight of powerpack 140 and because cannon assembly 210 andpowerpack 140 are both mounted to tank assembly 180 rather than to theair frame or fuselage of the aerial vehicle itself, system 200 provideseasier integration with a variety of air frames. In other embodiments,cannon assembly 210 and/or powerpack 140 may be mounted instead directlyto the airframe of the aerial vehicle. In the embodiment shown in FIGS.12-14, operator station 240 is mounted to platform 260 or floor of theaerial vehicle. In other embodiments, operator station 240 may bemounted on a rail, such as rail system 170 described above.

Tank assembly 180 is configured to house or support water tank 20, foamtank 30, and foam pump 32, as well as system plumbing and conduit,baffles, sensors, interfaces, interconnects, and the like. For example,tank assembly 180 includes interface 262 and associated plumbingconnected thereto for communicating water/foam solution 182 from watertank 20 to water/foam pump 290 of powerpack 140, and interface 264 andassociated plumbing connected thereto for receiving water/foam solution182 discharged from water/foam pump 290 and communicating water/foamsolution 182 to flexible conduit 266 and ultimately to boom 100 fordischarge toward a target.

Tank assembly 180 may also include an anti-cavitation device mountedinside water tank 20 at the lowest point of tank 20 to permit water/foampump 290 to withdraw water/foam solution 182 without cavitatingwater/foam pump 290. In the case of a helicopter, the lowest point intank 20 may arise when the helicopter is in hover mode.

As shown in FIGS. 15-17, tank assembly 180 may additionally beconfigured to interface with retractable pump system 350 for deployingand retracting a collapsible, flexible hose to draw water from a watersource, such as a pond or lake, into water tank 20 while the aerialvehicle is hovering over the water source. In one embodiment,retractable pump system 350 includes housing 352 for supportingmotorized reel 358 and reversible motor 360, and motor controller 361,for deploying or retracting collapsible hose 362. Housing 352 mayinclude panels 354 fastened to cage elements 356 to form the structureof housing 352. On the distal end of collapsible hose 362 is pump 364,the inlet of which is covered by screen 365, for pumping water from thewater source to water tank 20. Retractable pump system 350 may bemounted to the aerial vehicle or to a side of tank assembly 180 toconduct water from collapsible hose 362 to water tank 20 via conduit366.

Retractable pump system 350 is controllable from a pilot of the aerialvehicle or from an operator located at operator station 240. Duringoperation, reversible motor 360 of retractable pump system 350 may becommanded by the operator, which command is received by motor controller361, which in turn, energizes reversible motor 360 to cause rotation ofreel 358 in the desired direction to either wind and retract, or unwindand deploy, collapsible hose 360 to or from reel 358. Once pump 364 issubmerged in a water source following deployment of collapsible hose 362from reel 358, the operator may turn pump 364 “on” to pump water fromthe water source to water tank 20 via collapsible hose 362, internallythrough the hub of reel 358, and via conduit 366. Interface 368 ofconduit 366 may be mounted to a wall or interface associated with watertank 20 to communicate water to water tank 20. Conduit 366 mayalternatively be adapted to connect with additional plumbing, which inturn, is connected to water tank 20 to communicate the water to watertank 20. Upon completion of the filling cycle, the operator may commandpump 364 to its “off” position to cease pumping water. The operator maythen command reversible motor 360 to cause counter-rotation of reel 358to retract collapsible hose 362 and to wind collapsible hose 362 ontoreel 358. Deployment and retraction of collapsible hose 362 may beinitiated while the aerial vehicle is hovering, or in transition to andfrom hover, respectively, over the water source. One or more of thesteps of deploying collapsible hose 362 to, for example, a predeterminedlength, turning on and off pump 364 for pumping of water, and retractingcollapsible hose 362 may be automatically performed using sensors and/orappropriate software control algorithms incorporated into system 200.When collapsible hose 362 is fully wound on reel 358, retractable pumpsystem 350 does not interfere with normal landing operations for theaerial vehicle.

Cannon assembly 210 of system 200 includes turret 110, boom 100 havingnozzle 130 at a distal end, and optionally, infrared vision apparatus115 and distance measuring apparatus 120. As shown in FIG. 18, turret110 of system 200 includes linear actuator 212 and rotary actuator 214that may be programmed to control the direction and speed of movement ofboom 100 and turret 110, respectively, via joystick 250 (see, e.g., FIG.19). Turret 110 includes base 225, which in turn, is supported bysupports 227 (see, e.g., FIG. 18) for supporting and mounting cannonassembly 210 to tank assembly 180.

Base 225 includes stationary gear 220 for receiving gear belt 218, whichin turn, is connected to rotary actuator 214 for rotating turret 110along a generally vertical axis to cause boom to move horizontally.Turret 110 includes a bearing (not shown) upon which housing 222 and theremainder of turret 110 is supported. Consequently, when rotary actuator214 engages gear belt 218, housing 222 and the remainder of turret 110rotates in the direction of travel of rotary actuator 214 relative tobase 225.

To move boom 100 vertically, linear actuator 212 is connected to pivotarm 230, which in turn, is connected to boom 100. Compound (diagonal)movement of boom 100 may be achieved by engaging linear actuator 212 androtary actuator 214 simultaneously, perhaps at different rates. Gassprings 232 are connected to boom 100 to assist linear actuator 212 toreturn boom 100 to the horizontal position, such as in the event of apower failure. Battery 234 is configured to supply backup power toturret 110 to enable system 200 to automatically stow, allowing thepilot, onboard operator, or remote operator to manually stow, boom 100in a safe, forward-projecting configuration for egress of the airvehicle on-station and for landing of the air vehicle should the airvehicle or system 200 otherwise lose electrical power.

As previously described, infrared vision apparatus 115 includinginfrared camera 117 may be mounted on boom 100 or elsewhere on turret110. Likewise, distance measuring apparatus 120 comprising a laser fordetermining the distance between the aerial vehicle and any obstructionsor buildings, is shown mounted on base 225, but could be mounted on anystructure of system 200 or on the aerial vehicle itself.

Turning to FIG. 19, operator station 240 is shown as including chair 150for an operator of cannon assembly 210 and a group of controls andcomputer displays mounted on adjustable arm 242. The operator maymanipulate the aim point of boom 100 using, for example, a joystick 250.Joystick 250 is electrically connected to linear actuator 212 and rotaryactuator 214 to provide horizontal, vertical, and diagonal movement ofturret 110. Joystick 250 also includes a number of controls to activateor deactivate various aspects of cannon assembly 210. For example,joystick 250 shown in FIG. 19 includes trigger 252, which is connectedto one or more valves or solenoids to turn on, turn off, or vary theflow of water 24, water/foam solution 182, or water/foam/gas mixture 98delivered by boom 100 toward a target. Joystick 250 also includes button254 that is connected through a solenoid for releasing turret 110 from alocked and/or stowed position. Joystick 250 further includes rockerswitch 256 for turning on or turning off gas flow from gas generator274. One of ordinary skill would appreciate that other means for turningon or turning off various aspects of system 200 may be used other thanbuttons, switches, and the like, such as a software-driven userinterface deployed on a touch screen, as described below.

Operator station 240 also includes controls to permit an operator to,for example, turn on, turn off, or vary the flow of foam from foam tank30 to water tank 20 via foam pump 32. Operator station 240 may also havecontrols for varying the concentration of foam or foam concentrate toachieve a desired concentration of foam in water tank 20.

Also mounted on adjustable arm 242 is one or more displays 258 fordisplaying information and for providing an interface for an operator tocontrol one or more aspects of system 200. By way of example, displays258 may report data from infrared vision apparatus 115, distancemeasuring apparatus 120, position and movement data of boom 100, flowrate, quantities, and quantity remaining of consumable fluids and gases,data regarding the computed time remaining on-station, alert informationincluding data and/or messages indicating one or more operatingparameters of cannon assembly 210 falling outside predetermined limits,data related to atmospheric conditions such as wind direction and speed,temperature, humidity, and barometric pressure, and data relating toaltitude, attitude and other performance parameters of the aerialvehicle itself.

Displays 258 may also provide or incorporate a user interface forreceiving operator commands regarding the operation of system 200. Forexample, displays 258 may be configured with a touch sensitive screenfor receiving operator input to control or monitor one or more aspectsof system 200. Displays 258 may be connected to one or more CPU's,memory, data buses, and software configured to respond to and/or carryout the operator's commands.

System 200 may additionally be configured for remote monitoring oroperation of one or more aspects of system 200, such as boom 100. Forexample, system 200 may be configured to transmit and receive wirelessdata signals in real-time via satellite, cellular, or W-Fi, for example,including any or all of the information displayable on displays 258 to aremote operator or monitor located on the ground or in the air.

Turning now to FIG. 20, there is shown a schematic of one embodiment ofsystem 200 including tank assembly 180, powerpack 140, and cannonassembly 210. Tank assembly 180 includes housing 238 (see, e.g., FIGS.10-14) for housing and/or supporting water tank 20 and foam tank 30.Foam tank 30 may be mounted in, on, or to housing 238, whereas watertank 20 is housed within housing 238. In other embodiments, foam tank 30may be housed elsewhere on system 200 or the aerial vehicle. Tankassembly 180 also includes foam pump 32, which like foam tank 30, may bemounted in, on, or to housing 238, or may be mounted elsewhere on system200 or the aerial vehicle. Using foam pump 32, as directed by theoperator using, for example, one of the controls discussed above atoperator station 240, foam or foam concentrate of a known amount isdrawn from foam tank 30 and added to a known amount of water in watertank 20 to create a water/foam batch mixture having a desiredconcentration of foam to water ranging from approximately 1% toapproximately 10%.

In a configuration of system 200, foam tank 30 comprises approximately5% to approximately 10% by volume of the amount of water carried inwater tank 20. As described above for system 10, the foam to water ratioof system 200 may range from a wet foam to a dry foam of approximately0.1% to approximately 10.0%, as directed by an operator of system 200.The foam to water ratio of system 200 may alternatively range fromapproximately 0.4% to approximately 1.0%.

Powerpack 140 includes gas generator 274, electric motor 272, water/foampump 290, and enclosure 270 for protecting these components from damage.Powerpack 140 is configured to provide water/foam/gas mixture 98 to boom100 at approximately 20 to approximately 150 gallons per minute (gpm).Enclosure 270 may be configured as a plurality of individuallyremovable, lightweight yet sturdy panels or panel subassemblies toenclose or partially enclose powerpack 140.

FIGS. 21-24 better illustrate some of the components of powerpack 140including gas generator 274. Like gas generator 70 discussed above, gasgenerator 274 is configured to produce gas to aid in the creation oftightly-formed foam bubbles of an optimum size with water/foam solution182 before ejection of the mixture from nozzle 130 of boom 100 and toaid in achieving the greatest possible distance of the water/foam/gasmixture downrange of nozzle 130. To produce gas, gas generator 274differs from gas generator 70 in that it includes a store of liquidnitrogen that is passed through a heat exchanger to cause the liquidnitrogen to rapidly reach its boiling point to produce nitrogen gas inan amount equal to approximately 700 times the volume of liquidnitrogen.

More particularly, gas generator 274 of system 200 includes dewar 276for receiving and storing a quantity of liquid nitrogen aboard theaerial vehicle. In one embodiment, dewar 276 having model number10C-0012-75, which is available from Essex Aerospace, is anapproximately 22 inch vessel that is capable of holding approximately 20gallons of liquid nitrogen, and weighs approximately 85 lbs empty andapproximately 275 lbs when filled with liquid nitrogen.

Dewar 276 includes a pressure build cycle to continuously pressurize theullage space above the liquid nitrogen level for pressurized delivery ofthe liquid nitrogen to heat exchanger 278, and includes safety devicessuch as one or more pressure relief valves and burst valves to preventover pressurization of dewar 276. To pressurize the liquid nitrogen, avalve at or near the bottom of dewar 276 is opened to allow a portion ofthe liquid nitrogen stored in dewar 276 to be directed to a heatexchanger built into or on dewar 276 to create nitrogen gas that is thenreturned to the top of dewar 276 to pressurize the ullage space. Thisprocess, together with one or more pressure relief valves, maintains adesired pressure in dewar 276 whenever liquid nitrogen is being drawnfrom dewar 276 during operation of system 200.

Upon opening valve 286, as directed by an operator using, for example,one of the controls discussed above at operator station 240, conduit 288directs liquid nitrogen 287 from dewar 276 to coil 279 of heat exchanger278, which is shown with its housing removed for clarity. At the sametime, water/foam solution 182 at ambient temperature from water tank 20is drawn by water/foam pump 290 to inlet 294 and through heat exchanger278 to cause liquid nitrogen 287 in coil 279 to rapidly reach itsboiling point to generate nitrogen gas 289. The water/foam solution 182is then drawn by water/foam pump 290 via conduit 292 and expelled bywater/foam pump 290 at discharge 296. Nitrogen gas 289 exiting heatexchanger 278 is then injected into water/foam solution 182 downstreamof water/foam pump 290 at point 284 in an amount of approximately 75scfm and at approximately 150 psi. The injection of the 150 psi nitrogengas 289 compresses water/foam solution 182 for delivery through conduit266 to boom 100. In addition, water/foam solution 182 exiting heatexchanger 278 may be slightly colder than ambient as a result of theheat exchange with the liquid nitrogen 287, which may aid suppression ofa fire when ejected from boom 100. Dewar 276 having a 20 gallon liquidnitrogen capacity will provide approximately 75 scfm at approximately150 psi of nitrogen gas 289 to provide approximately 1 hour of operationof system 200 on a target. Dewar 276 may be scaled in physical size andcapacity, either larger or smaller, along with the other elements ofsystem 200, to accommodate the payload carrying capacity of the aerialvehicle on which it is mounted.

Water/foam pump 290 may be configured as a centrifugal pump with aradial flow impeller. To drive water/foam pump 290, as best shown inFIG. 24 with dewar 276 and other hardware removed for clarity, powerpack140 includes electric motor 272 directly coupled to water/foam pump 290with coupler 271. Electrical power to operate system 200, includingcannon assembly 210, operator station 240, and powerpack 140 includingelectric motor 272, may be obtained from the electrical bus of theaerial vehicle, from an electrical generator connected to the engine ortransmission of the aerial vehicle, or from an auxiliary power unit(APU). In the embodiment of FIGS. 21-24, electric motor 272 isconfigured to turn at approximately 8000 RPM, while water/foam pump 290is configured to turn at a rated speed of approximately 9400 RPM.Consequently, to operate water/foam pump 290 at maximum rated speedwithout overspeeding electric motor 272, electric motor 272 may becoupled to a gearbox, which in turn, may be coupled to water/foam pump290. In one embodiment, electric motor 272 comprising model number6200-10 available from K-Tech provides 30 HP at 7800 RPM while drawingapproximately 75 amps at 115/200 VAC, 3-phase at 400 Hz, and weighsapproximately 70 lbs and measures approximately 18 inches long×12 incheswide×11.5 inches high.

For compact assembly of powerpack 140, base 298 having stanchions 299may be connected to base 280 to raise and support dewar 276 aboveelectric motor 272, water/foam pump 290, and heat exchanger 278. Bracket273 may be connected to base 280 to support electric motor 272. Brackets277 may be connected to base 280 to support heat exchanger 278.

Gas generator 274 of system 200 is configured for either quick refill ofdewar 276 through intake valve 275 or by swapping empty dewar 276 with afull one. Plumbing and wiring to dewar 276 having quick disconnectfeatures may assist the replacement of dewar 276.

In one embodiment of system 200 comprising gas generator 274 havingdewar 276, where dewar 276 is sized to hold approximately 20 gallons ofliquid nitrogen, water tank 20 is sized to hold approximately 800gallons of water, foam tank 30 is sized to hold approximately 80 gallonsof foam or foam concentrate, the dry weight of system 200 isapproximately 1080 lbs, and when fully loaded with consumables, such asliquid nitrogen, water and foam, the weight of system 200 isapproximately 7890 lbs. At an approximately 0.5% foam to water ratio,system 200 having this configuration is capable of 5 minutes of useon-station.

Turning now to FIG. 25, there is shown a schematic of another embodimentof system 200 including tank assembly 180, powerpack 140, and cannonassembly 210. In this embodiment, powerpack 140 includes gas generator310, which unlike gas generator 274, which generates nitrogen gas 289 tocompress water/foam solution 182, water/foam pump 290 of gas generator310 draws in atmospheric air and pressurizes the air along withwater/foam solution 182. As best shown in FIG. 26, system 200incorporating gas generator 310 provides for a more compact powerpack140 and reduces weight and system complexity over system 200incorporating gas generator 274, but potentially with a slight decreasein quality of foam due to slightly less air volume to pressurizewater/foam mixture 182.

More particularly, gas generator 310 of system 200 includes adjustableair induction valve 315 connected to water/foam pump 290, which isdriven by electric motor 272. As directed by an operator using, forexample, one of the controls discussed above at operator station 240,water/foam pump 290 is triggered “on” to draw water/foam solution 182from water tank 20. At the same time, air induction valve 315 may beautomatically or manually commanded to its “open” position, wherebyatmospheric air 316 is drawn into the suction side of water/foam pump290 at point 320 at the rate of approximately 30 CFM to approximately 50CFM. In one embodiment, air induction valve 315 comprises anelectrically variable valve opening, controllable by an operator, tovary the amount of air introduced into the suction side of water/foampump 290 while water/foam pump 290 is driven at a constant speed.

Water/foam pump 290 then pressurizes air 316 along with water/foamsolution 182 to approximately 125 psi and expels the pressurizedwater/foam/air solution 325 at discharge 296 at approximately 150 gpm.The introduction of air 316 by system 200 for mixing with andpressurization of water/foam solution 182 for delivery through conduit266 to boom 100 aids in the creation of tightly-formed foam bubbles ofan optimum size before ejection of the mixture from nozzle 130 of boom100 and to aid in achieving the greatest possible distance of themixture downrange of nozzle 130. Because water/foam pump 290 turns at arelatively high speed of approximately 9400 RPM, it does not appreciablylose suction when drawing in the approximately 30-50 CFM of air 316along with water/foam solution 182. And because air 316 is a limitlessresource when drawn from the atmosphere, time on-station over a target,such as a fire, would be limited to the amount of other consumablescarried aboard the aerial vehicle, such as water, foam, or fuel.Consequently, system 200 including gas generator 310 provides asimplified, highly efficient means for providing compressed air foamaboard aerial vehicles for use in engaging a target.

In one embodiment of system 200 comprising gas generator 310, wherewater tank 20 is sized to hold approximately 800 gallons of water, foamtank 30 is sized to hold approximately 80 gallons of foam or foamconcentrate, the dry weight of system 200 is approximately 1015 lbs, andwhen fully loaded with consumables, such as water and foam, the weightof system 200 is approximately 7580 lbs. At an approximately 0.5% foamto water ratio, system 200 having this configuration is capable of 5minutes of use on-station.

Turning to FIGS. 28-30 illustrate the integration of system 200 with ahelicopter. Tank assembly 180 of system 200 is shown mounted externallyto helicopter 330 along the underside of the fuselage. Cannon assembly210 with turret 110 and boom 100 is shown with boom 100 in the stowedposition along the starboard side of helicopter, with nozzle 130 of boom100 pointed in the direction of the nose of helicopter 330. Powerpack140 is shown mounted to tank assembly 180 on the port side of helicopter330, opposite cannon assembly 210 to counterbalance the weight of cannonassembly 210. System 200 is positioned aft of the nose of helicopter 330at or near the helicopter's center of gravity. System 200 is configuredto optimize the flying characteristics of helicopter 330 with system 200attached thereto and throughout the operation of system 200 andhelicopter 330.

While specific embodiments have been described in detail, it will beappreciated by those skilled in the art that various modifications andalternatives to those details could be developed in light of the overallteachings of the disclosure. Accordingly, the disclosure herein is meantto be illustrative only and not limiting as to its scope and should begiven the full breadth of the appended claims and any equivalentsthereof.

What is claimed is:
 1. A fire suppression apparatus for fighting firesfrom a helicopter, comprising: a tank assembly comprising (a) a foamtank for housing a foam and configured for attachment to the helicopter,(b) a water tank located downstream of the foam tank for housing waterand configured for attachment to the helicopter, wherein the water tankis configured to receive a foam from the foam tank that when mixed withwater in the water tank forms a liquid fire retardant in the water tank,and (c) a tank assembly housing that encases the foam tank and the watertank; a centrifugal pump with a radial outflow impeller mountable to thehelicopter and driven by an electric motor, the pump including an airinduction valve with an electrically variable valve opening connected toa suction end of the pump, wherein air and the fire retardant are drawninto the suction end and pressurized by the pump; and a cannon assemblyincluding an aimable boom mountable to the helicopter and connected tothe pump by a conduit, the boom including a nozzle on a distal end ofthe boom from which the pressurized fire retardant and air is dispensedtoward a target.
 2. The fire suppression apparatus of claim 1, whereinthe centrifugal pump is supported on a flat upper surface of a base, andthe base is cantileverly mounted to the tank assembly via a pair ofbrackets.
 3. The fire suppression apparatus of claim 2, wherein at leastone of the brackets includes a surface defining a plurality of recessesfor reducing weight of the at least one of the brackets.
 4. The firesuppression apparatus of claim 1, wherein the centrifugal pump isconfigured to rotate at 9400 rotations, or more, per minute.
 5. The firesuppression apparatus of claim 1, wherein the centrifugal pump has anaxial inlet.
 6. The fire suppression apparatus of claim 1, wherein theair reaching the centrifugal pump via the air induction valve does notpass through an air compressor.
 7. The suppression apparatus of claim 6,wherein the air induction valve includes an inlet that directly receivesunpressurized ambient air.
 8. The fire suppression apparatus of claim 1,including one or more electronic controllers in operative communicationwith the electric motor and the air induction valve, wherein the one ormore electronic controllers are configured to automatically open the airinduction valve upon activation of the centrifugal pump.
 9. The firesuppression apparatus of claim 1, including a foam pump configured topump foam from the foam tank to the water tank, wherein the tankassembly housing encases the foam pump.
 10. The fire suppressionapparatus of claim 1, wherein each of the foam tank and the water tankhave an interior volume for holding fluid and the interior volume of thefoam tank is five to ten percent of the interior volume of the watertank.
 11. The fire suppression apparatus of claim 1, wherein the boom isconfigured to extend at least one meter beyond an outer tip of a rotorof the helicopter.
 12. The fire suppression apparatus of claim 11,including a primary power source for supplying electrical power to thecannon assembly and a separate battery for supplying backup electricalpower to the cannon assembly.
 13. The fire suppression apparatus ofclaim 1, wherein the cannon assembly includes a turret having a linearactuator, a rotary actuator, a gear belt connected to the rotaryactuator, and a bearing supporting a turret housing.
 14. The firesuppression apparatus of claim 13, wherein the cannon assembly includesa pivot arm connected to the linear actuator and one or more gas springsconnected to the boom.
 15. The fire suppression apparatus of claim 1,wherein the water tank includes an anti-cavitation device.
 16. The firesuppression apparatus of claim 15, wherein the anti-cavitation device ismounted inside the water tank at a lowest point of the water tank. 17.The fire suppression apparatus of claim 1, including a retractable pumpsystem configured to deploy and retract a flexible hose, wherein theretractable pump system includes a pump housing supporting a motorizedreel and a reversible motor, and wherein the pump housing includespanels fastened to cage elements.
 18. A fire suppression apparatus forfighting fires from a helicopter, comprising: a tank assembly comprising(a) a foam tank for housing a foam and configured for attachment to thehelicopter, (b) a water tank located downstream of the foam tank forhousing water and configured for attachment to the helicopter, whereinthe water tank is configured to receive a foam from the foam tank thatwhen mixed with water in the water tank forms a liquid fire retardant inthe water tank, and (c) a tank assembly housing that encases the foamtank and the water tank; a centrifugal pump with a radial outflowimpeller mountable to the helicopter and driven by an electric motor,the pump including an air induction valve with an electrically variablevalve opening connected to a suction end of the pump, wherein air andthe fire retardant are drawn into the suction end and pressurized by thepump; and a cannon assembly including an aimable boom mountable to thehelicopter and connected to the pump by a conduit, the boom including anozzle on a distal end of the boom from which the pressurized fireretardant and air is dispensed toward a target.
 19. The fire suppressionapparatus of claim 18, wherein the centrifugal pump is supported on aflat upper surface of a base cantilevered via a pair of brackets, and atleast one of the brackets includes a surface defining a plurality ofrecesses for reducing weight of the at least one of the brackets.
 20. Afire suppression helicopter, comprising: a tank assembly comprising (a)a foam tank for housing a foam and configured for attachment to thehelicopter, (b) a water tank located downstream of the foam tank forhousing water and configured for attachment to the helicopter, whereinthe water tank is configured to receive a foam from the foam tank thatwhen mixed with water in the water tank forms a liquid fire retardant inthe water tank, and (c) a tank assembly housing that encases the foamtank and the water tank; an axial inlet centrifugal pump with a radialoutflow impeller mounted to the helicopter and driven by an electricmotor, the pump including an air induction valve with an electricallyvariable valve opening connected to a suction end of the pump, whereinair and the fire retardant are drawn into the suction end andpressurized by the pump, and the air reaching the centrifugal pump viathe air induction valve does not pass through an air compressor; and acannon assembly including an aimable boom mounted to the helicopter andconnected to the pump by a conduit, the boom including a nozzle on adistal end of the boom from which the pressurized fire retardant and airis dispensed toward a target, wherein the boom is configured to extendat least one meter beyond an outer tip of a rotor of the helicopter.